Using a " wall " of quark point sources, we invert the chirally improved Dirac operator to create an " incoherent " collection of quark propagators which originate from all spatial points of the source time slice. The lowest-order NRQCD approximation is used to create heavy-quark propagators from the same wall source. However, since the numerical cost involved in computing such heavy-quark prop...

The null energy condition (NEC), an important assumption of the Penrose singularity theorem, is violated by quantum fields. natural generalization NEC in field theory, renormalized averaged over a finite segment, known to be unbounded from below. Here, we propose alternative, double smeared (DSNEC), stating that two directions has lower bound. We rigorously derive DSNEC general worldvolume boun...

This paper presents a model and implementation techniques for speeding up constraint propagation. Two fundamental approaches to improving constraint propagation are explored: keeping track of which propagators are at fixpoint, and choosing which propagator to apply next. We show how idempotence reasoning and events help track fixpoints more accurately. We improve these methods by using them dyn...

Using a " wall " of quark point sources, we invert the chirally improved Dirac operator to create an " incoherent " collection of quark propagators which originate from all spatial points of the source time slice. The lowest-order NRQCD approximation is used to create heavy-quark propagators from the same wall source. However, since the numerical cost involved in computing such heavy-quark prop...

The nucleon is described as a bound state of a quark and an extended diquark. Hereby the notion “diquark” refers to the modelling of separable correlations in the two–quark Green’s functions. Binding of quarks and diquarks takes place via an exchange interaction and is therefore related to the Pauli principle for three– quark states. Fully Poincaré covariant nucleon amplitudes are calculated fo...

We develop the perturbation theory for propagators, with the objective to prove Gaussian bounds. Let U be a strongly continuous propagator, i.e., a family of operators describing the solutions of a non-autonomous evolution equation, on an Lp-space, and assume that U is positive and satisfies Gaussian upper and lower bounds. Let V be a (time-dependent) potential satisfying certain Miyadera condi...

We extend our new approach for numeric evaluation of Feynman diagrams to integrals that include fermionic and vector propagators. In this initial discussion we begin by deriving the Sinc function representation for the propagators of spin1 2 and spin-1 fields and exploring their properties. We show that the attributes of the spin-0 propagator which allowed us to derive the Sinc function represe...

We study numerically the Schwinger-Dyson equations for the coupled system of gluon and ghost propagators in the Landau gauge and in the case of pure gauge QCD. We show that a dynamical mass for the gluon propagator arises as a solution while the ghost propagator develops an enhanced behavior in the infrared regime of QCD. Simple analytical expressions are proposed for the propagators, and the m...